This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Despite treatment, cognitive and motor deficits are common in individuals with inherited disorders of metabolism that affect processing of proteins, carbohydrates, and fats. However, the extent to which the deficits involve specific cognitive or sensorimotor domains is unknown. Furthermore, little is known about the neurochemical basis of cognitive impairment in these disorders. This project will investigate cognitive and motor dysfunction in inborn errors of metabolism utilizing state of the art neuroimaging to examine the underlying neural basis that may elucidate these defects. In particular, this study will address differences in cognition and biochemistry in individuals personally affected with inborn errors of metabolism, as well as heterozygous carriers of the disease, who may or may not manifest symptoms, depending upon the mechanism of inheritance. This study will be performed in the Neuroimaging center at Georgetown University, and GCRC . Imaging studies will be complemented with molecular and biochemical parameters. Such methods of investigation may serve as a model for studying the relationship between genes, biochemical markers, brain function, and behavior in metabolic diseases. The results of this study should help to optimize the care and/or treatment of individuals with inborn errors of metabolism, and serve to identify biomarkers of disease which can be used to monitor response to therapies.